Only one track per file implemented yet

This uses some unspecified C++ statically linked version of GME.
That does not correspond to libgme, and seems unused.

Our PO files are all encoded in UTF-8, and VLC always binds its text
domain as UTF-8. There is no need to convert localized strings. So
libintl does not need to use iconv.

This should help a lot the future work.

We can't use the VLM object because the instances and their input
resources are cleaned up in the VLM destructor

This reverts commit d38706da.

Changed back, as changed loop didn't do same as original did

Also assume p_item->i_es is set correctly

- use switch/case instead of if/else if/else if
- factor out HandleEditBoxKey() and HandleCommonKey()
- return bool instead of int

Use one line per switch label when it improves readability
Also explicit the sign of position increment even when positive so +x and -x are aligned

And cleanup includes of StandardPanel

Remove friendship
Factorisation of CoverArt
Reduction of class footprints
virtual and protected correctness
Forward declaration when possible

It's useless and create bogus empty commands, that output ugly blank
lines and crap during login